Automobiles and other vehicles have come to employ safety systems which include radar technologies for detecting a location of an object or target with respect to the vehicle so that a driver or collision-avoidance device can react accordingly. A radar system includes a transmitter for sending out a source signal and a receiver for receiving an echo or reflection of the source signal from the target. The received signal is sampled at a selected sampling frequency and the sampled data points of the received signal are entered into a Fast Fourier Transform (FFT) in order to determine the frequency of the returning signal. A range or relative velocity of the target with respect to the vehicle can be determined from this frequency.
A maximum range at which a target's location can unambiguously be determined is related to a highest frequency component of the echo signal. Frequencies above a Nyquist frequency (which is related to the highest frequency component) are often filtered out of the frequency space prior to distance determination because such frequencies are considered to be aliased frequencies related to false distance readings. To increase an unambiguous range, new hardware having higher radar frequencies and higher sampling rates can be installed in the vehicle. However, such hardware and installations increase the cost of the vehicle. Accordingly, it is desirable to provide a method for increasing a range and/or resolution of a radar signal using existing radar systems.